Documents DE 197 57 763 and EP 104 2643 discuss how the travel axis and the wheel geometrical data and the axle geometrical data may be ascertained with the aid of cameras, a reference coordinate system at the test site and optical features at the vehicle wheels and at the body. Both methods require a reference coordinate system, and rely on the measurement using binocular (stereo) picture recording devices. Such binocular picture recording devices require much effort and are costly.
U.S. Pat. No. 6,134,792 discusses an axis measuring system that relies on monocular picture recording devices. In order to obtain the three-dimensional information on the wheel position, optical targets are applied on the wheels on which features are located whose position is known in a local target coordinate system. The targets having these features are produced using high precision, and form a so-called pass point system. The production of such high-precision targets is costly. In an everyday repair shop environment, the high precision targets are easily damaged or deformed, which leads to uncontrollable measuring errors.